Condition Based Maintenance (CBM) is a developing thrust in applications for high performance sliding bearings. It is especially important for aerospace flight critical applications such as but not limited to helicopter rotor pitch link control bearings. Bearing wear rate can be influenced by bearing design, quality, application, and various performance and environmental flight conditions. Therefore it is currently relatively difficult to predict with reasonable certainty any particular bearing's condition based on flight hours alone.
There is also presently an increase in helicopter fly-by-wire, hydraulic, pitch control which has essentially eliminated mechanical rotor haptic feedback to the pilot. These changes have reduced the pilot's ability to judge when there may be a developing pitch control bearing problem due to bearing wear.
An active bearing wear sensor configuration is therefore useful to allow the bearing to more accurately signal when certain benchmarks are identified, such as reduction of bearing wear surfaces to a given threshold or other parameters associated with bearing performance and use. Such a solution to the problem of accurately monitoring bearing performance, and specifically in an aeronautical environment, would also likely reduce the relatively expensive and relatively more unreliable task of mechanical gauging of rotor bearings. Such mechanical gauging inspections typically result in substantial accumulated cost and down time for the aircraft over the life of given bearing placement.